Hub, especially for bicycles and the like

ABSTRACT

The invention relates to a hub for bicycles and the like, comprising a hub axle and a hub housing concentrically mounted in relation thereto including a bearing device having at least two bearings mounted between the axle and the housing. A rotor ( 25 ) for receiving at least one toothed wheel is disposed on the hub axle ( 4 ) and a free-wheel device is arranged between the rotor and the housing of the hub, said device having two toothed discs ( 22, 23 ), the toothed surfaces of which are pressed against each other by a pretensioning device. The toothed surfaces of which are pressed against each other by a pretensioning device. The toothed discs are mounted ina substantially concentric manner in relation to the hub axle ( 4 ) on planes which are aligned perpendicular to the hub axle. The toothed discs are float mounted or fixed so that the toothed discs can be tilted in relation to the hub axle.

The present invention relates to a hub, which is especially suitable forbicycles.

In addition to bicycles, the hub can be used for other purposes, forexample for all types of towing trailers, especially bicycle trailers,for wheelchairs and other such similar contrivances. For the sake ofsimplicity, however, the invention will be described in the followingwith reference to its use with bicycles, whereby said description shallnot be construed in any way as a limitation of application.

Hubs of the type referred to here serve to connect the stationary wheelaxle with the freewheel rotating about said axle. The connection betweenthe hub and the rim of the wheel is made with steel spokes, wherebygenerally between 24 and 36 spokes are used which are inserted intobores on the hub and the rim in adherence to a given pattern. Inaddition to said spokes, connections today are increasingly making useof just a small number of, for example, three or four plastic supports,or employing discs such as carbon discs.

High demands are placed on hubs especially with wheels used for sportingpurposes, most particularly with wheels used during competitive events.On one hand, a hub should rotate with the least amount of frictionaldrag possible and on the other hand, it should enable a support as freeof play as possible, it should exhibit only slight soiling and wear, andit should be easy to mount and disassemble.

Generally, it is the rear wheel of a bicycle which is driven. To thisend, in addition to the actual hub housing, a rotor or driver is alsoarranged on the rear wheel hub axle, to which one or more gearwheels orsprocket wheels can be firmly mounted in order to transfer the drivingforce to the rear wheel.

To prevent the front pedal crank from continuing to rotate during adownhill ride, a freewheel is usually integrated into the rear hub,which transfers the driving force of the driver or the rotor from therotor to the hub housing and thus to the rear wheel while having theeffect that the hub housing and the rotor can rotate counter to oneanother during back-pedaling.

A freewheel which is fast and reliable in the introducing of drivingforce transferred from the rotor to the hub housing is known in theprior art from German utility model G 94 19 357.6. Meanwhile, frictionlosses are also relatively slight, if the user does not use the pedal.

This freewheel transfers forward rotor torque via a pair of tootheddiscs while the gear teeth are disengaged during back-pedaling.

A disadvantage of this freewheel is that a slight tilting of one of thetoothed discs leads to greater wear on the more heavily stressed teethso that durability is limited.

The task of the present invention is to provide a hub for a bicyclewhich meets the previously mentioned requirements and which, inparticular, functions reliably, is easy to dismantle and which has ahighly durable life.

This task is solved in accordance with the present invention by theobject of claim 1, claim 26, or claim 27. Preferred embodiments of theinvention constitute the subject matter of the subclaims.

The present invention provides a hub with high functional reliabilityand durability since the inventive freewheel contained in the hubachieves a reliable, durable and form-fitting connection duringtransferring of force while frictional losses occurring, for exampleduring a downhill ride when not pedaling, are slight.

The hub according to the present invention has two bearing means as afront wheel hub and preferably four bearing means as a rear wheel hub.These bearing means are preferably configured as ball bearings,especially preferred is their configuring as grooved ball bearings,whereby it is especially preferable to use low-friction bearings andlow-friction lubricants.

In addition to a hub axle which is rotatably mounted relative the hubhousing, the hub according to the present invention also has a rotormounted to be rotatable relative said hub axle and a freewheel devicecomprising at least two toothed discs arranged or switched between therotor and the hub housing, said discs being pressed against each otherby a pre-tensioning means and configured such that they transfer rotortorque in the direction of travel from the rotor to the hub housing. Ina preferred embodiment, the tooth surfaces are arranged on a sidesurface and engage with one another upon transmission of torque.

The toothed discs are arranged substantially concentric to the hub axleand when assembled accordingly, the discs lie substantially in a planeperpendicular to an axial line of said hub axle, at least in the stateof rest.

The toothed discs are of a floating mounting so that a tilting of saidtoothed discs perpendicular to the axial line relative this plane ispossible during operation.

The hub according to the present invention has numerous advantages.

The use of two floating-mounted toothed discs has the advantage that atilting of the first toothed disc causes a corresponding tilting of thesecond toothed disc such that the teeth arranged on said toothed discsare always reliably engaged with one another during a transmission oftorque.

In a preferred embodiment of the inventive hub, said toothed discs arearranged adjacent to one another and urged together by means of at leastone spring, whereby especially preferred is respective springs eachexerting pressure against each outer side of the respective adjacenttoothed discs. Configuring at least one of these springs as a coilspring is particularly preferred.

Such a configuration has many advantages since using two springsexerting pressure symmetrically from both sides onto adjacent tootheddiscs results in a symmetrical stressing and since using two springsallows for a quicker reaction at the outset. Consequently, the freewheelreacts faster to the introduction of driving force than conventionalfreewheels do.

In a further preferred embodiment, the toothed discs of the freewheelare configured to be relatively thin discs, their outer diameteramounting to between 20 and 40 mm; roughly 30 mm is preferred. Discthickness amounts to between 4 and 12 mm; roughly 8 mm is preferred. Aplurality of teeth are arranged on a side or disc surface, whereby thenumber of said teeth is >2, preferably between 4 and 60, and especiallypreferred between 6 and 48.

The quick and easy exchanging of toothed discs integrated in the hub isparticularly preferred, as is the hub itself being readily openedwithout great exertion, in order to enable simple and feasibly dailycleaning, as is customary in professional cycling circles.

A greater number of teeth leads to a higher freewheel loading capacity,while friction is smaller with a lesser number of teeth.

When the corresponding toothed discs allow for simple and quickreplacement, the user can choose between the individual advantagesaccording to his or her own requirements for use so that toothed discshaving a lesser number of teeth can be fitted for rides over evensurfaces or at high speeds, while a greater number of teeth is moreauspicious for uphill or cross-country rides since the loading capacityis greater.

In another preferred embodiment of the inventive hub, the teeth of thetoothed discs are arranged on an annular section of the disc or sidesurface, wherein arranging the teeth on one of the outer annular areasof the toothed disc is especially preferred.

Two toothed discs are employed in a preferred embodiment of theinventive hub which are essentially similar or identical or manufacturedin such a way that with two toothed-discs arranged with their toothsurfaces directly adjacent, at least a part of the teeth of one of saidtoothed discs engages in the recesses between the teeth of said secondtoothed disc, whereby the number of teeth of said two toothed discs mayeither be identical or different.

This constitutes a further advantage of the hub according to the presentinvention since the effect described above can be achieved by switchingthe toothed disc: employing a toothed disc with a lesser number of teethreduces friction, employing a toothed disc with a greater number ofteeth increases resistance.

The individual teeth are preferably configured to be asymmetrical. Along, flat incline having an angle of inclination of 5-30°, preferablyat about 11°±1°, forms one flank; the second flank of the tooth has anobtuse angle of about 100° to the disc surface.

Upon a transmission of torque in the direction of travel, the tootheddiscs are pressed together by the pre-tensioning means and the steepflanks of the teeth transfer the torque.

When back-pedaling, the flat ascending sides of the teeth slide pasteach other, disengaging the toothed discs.

In a further embodiment of the hub according to the present invention,the side surfaces of the toothed discs are configured such that twocontacting toothed discs are essentially in contact over a major portionof the disc surfaces.

In further embodiment of the inventive hub, the toothed discs aredisposed with a plurality of projections distributed about thecircumference of their outer surface in the radial direction which forma further radial gearing and which exhibit in the radial direction atriangular, rectangular, sinusoidal, trapezoidal or toothed-shapedcross-section in a plane of said toothed surfaces.

In another embodiment of the present invention, one of said tootheddiscs is essentially non-rotatably arranged in a substantiallyconcentric bore or opening in the rotor arranged to align to the centerof the hub in the corresponding assembly, and said rotor opening isconfigured such that said projections of said toothed discs extend intothe radial recesses of said rotor.

In the hub housing of the corresponding assembly, a bore or opening isarranged in substantially concentric alignment toward the rotor in whicha threaded ring comprising a bore is screwed into said hub housing, atoothed disc essentially non-rotatably arranged in said bore. Said borein the threaded ring is preferably configured such that the projectionsof the toothed disc project into the radial recesses of said threadedring.

These embodiments are particularly advantageous since one toothed discis arranged non-rotatably in the rotor, while the other toothed disc isarranged non-rotatably in the hub housing. When contacting one another,a forward torque can be transferred from the rotor to the first tootheddisc, from there to the second toothed disc, and from the second tootheddisc to the hub housing.

The bore in the rotor and the bore in the threaded ring are preferablyconfigured such that they are suited to receive only one toothed ring,effectively making it impossible for the toothed ring to switch from oneof said holes to the other.

In all of the embodiments described thus far, the toothed discs aredesigned for a predefined maximum number of teeth. In a toothed dischaving this maximum number of teeth, the teeth are evenly distributedcircumferentially on the side surfaces, whereas while a toothed discwhich has a lesser number of teeth has certain teeth omitted, theexisting ones lie on the same grid as a toothed disc having the maximumnumber of teeth.

The circumferential spacing can vary from-tooth to tooth, at least inthe case of a toothed disc having a number of teeth which cannot bedetermined from integral division of said maximum number of teeth.

A toothed disc with less teeth than the maximum can be fabricated inthat certain teeth be omitted preferably in symmetrical distributionacross the circumference, so that the circumferential spacing from onetooth to the next at these points is larger than at other points.

This configuration is of particular advantage since this measure allowstoothed discs having almost any, even differing, numbers of teeth to becoupled with one another.

In a further embodiment of the hub according to the present invention,the rotor can be removed manually without the need for any special tool.

This is especially advantageous since it is particularly simple for auser to exchange gearwheels.

In a preferred embodiment of the inventive hub, the threaded ring ismade of a metal alloy, preferably a light metal alloy; an aluminum alloyis especially preferred.

A light metal or an aluminum alloy is especially advantageous since thisreduces the weight.

At least a part of the areas which transfer force in the hub may be, forexample, additionally tempered through a surface treatment or similarmeasure. This is especially advantageous since it increases the servicelife and load capacity of the components.

A preferred embodiment of the invention provides a hub having highfunctional safety, since the sealing means provided in accordance withthe invention prevents the entry of water and dirt into the hub body andespecially prevents influx into the bearing means, or at least hinderssame to the greatest possible extent.

The phrase “hinders to the greatest possible extent” was chosen for thereason that a seal of this type can never be absolutely tight in theliteral physical sense. The seal is, however, especially in thepreferred configurations described in the following, designed such thatinfiltration of moisture and dirt is not possible during normal use norduring customary cleaning procedures.

According to a preferred embodiment, the sealing means is configured asa labyrinth seal. “Labyrinth seal” is to be understood as a seal inwhich the sealing surfaces moveable relative one another do not touch,but rather form a small seal gap inbetween. Said seal gap undergoes atleast one change of direction, preferably several deflections, in factpreferably at an angle of about 90°, so that infiltration of liquid ordirt is basically impossible when a sufficiently constricted seal gap ischosen.

The use of a labyrinth seal has the advantage that the seal is notdamaged or rendered ineffective even upon direct impact from a jet surgeof water. Mountain bikes in particular are regularly cleaned afteroff-road use using a high pressure cleaner which sends water impactingthe parts to be cleaned at a pressure of up to 150 bar. The multipledeflections to the labyrinth seal gap enable the water pressure createdby the impact to be rapidly and reliably, degraded so that said pressuredoes not damage the seal and the water cannot penetrate to the bearingsnor the hub interior.

In order to achieve a good sealing effect, it is preferable to have 3 or4 deflections of roughly 90°. It is, however, also possible to providefewer or more deflections.

According to another preferred embodiment, the sealing means isconfigured as an elastomer seal having an elastic lip and especiallypreferred is configuring the seal in essentially a V-shape. Hereby it ispreferable to design the part which moves relative to the part to besealed relatively thin so that an overlain elastic sealing surface orsealing lip exerting a relatively high pressure per surface area isattained which still generates only a low moment of friction.

According to an especially preferred embodiment, the sealing meanscomprises both a labyrinth seal as well as also an elastomer seal. Inthis case, it is preferable that the elastomer seal is downstream thelabyrinth seal; it is however also possible that this order be reversed.Downstream refers to the elastomer seal being closer to the bearing andthe labyrinth seal being farther away from the bearing and alignedtoward the surroundings.

This results in the advantage as described above of greatly restrictingthe infiltration of water and dirt through the labyrinth seal even, forexample, when employing a high-pressure cleaner, and that any possibleresidual amounts of fluid which could conceivably gain entrance to thehub through the labyrinth seal are prevented from penetrating on throughto the bearing by the elastomer seal.

It is further preferred, particularly when making use of a labyrinthseal, to configure the sealing gap and all surfaces coming into contactwith said sealing gap such that the centrifugal force generated by therotation of the hub body can be used to expel any water which haspenetrated the labyrinth seal back outside.

Also in the case of a combination of a labyrinth seal with a downstreamelastomer seal, the surfaces of the seal gap and the surfaces of theelastomer seal are accordingly configured so that the conveying ofinfiltrated water back outward functions in a simple and reliablemanner.

Particularly when using such a hub in competitive situations, it isabsolutely essential that the hub be regularly dismantled despite goodsealing effect in order to ensure that the bearings are in optimalcondition. Complicated special tools are at times required to enabledismantling of conventional hubs, impeding regular maintenance.

The present invention therefore proposes structuring the hub such thatit can be dismantled without the need for any tools, or at least for themost part without tools, or at least without the need for any specialtools.

This is achieved according to a preferred embodiment of the invention inthat the bearing is retained by a stopper element which itself ispreferably retained only by friction. Said stopper element is preferablydesigned rotationally symmetrical to the axle itself and slid onto samewhereby the retaining function is then generated by means of africtional resistance between said stopper element and axle. Theretaining function is preferably created by means of a gasket,preferably a conventional O-ring, which simultaneously affects a sealingrelative stopper element and axle.

This configuration has the advantage that the stopper element with thesealing ring can be positioned on the axle and removed from same withoutthe need for tools. At the same time, the corresponding configuration ofthe sealing ring allows for attaining a high moment of retention inorder to hold the stopper element securely to the axle.

It is pointed out only for the sake of completeness that the stopperelement in this configuration is structured such that it is retained atthe inner side of the drop-outs in which the hub is held in the frontwheel fork, respectively in the rear construction when the hub is inmounted state, and thus secured by the fitted screw connection,respectively quick-release means retaining the axle and hub in thedrop-out.

Further advantages, features and application possibilities of thepresent invention will now ensue from the following description of anembodiment making reference to the drawings, which show:

FIG. 1 an embodiment of a hub for a rear wheel in accordance with thepresent invention;

FIG. 2a an enlarged detail view of the representation according to FIG.1;

FIG. 2b an enlarged detail view of the representation according to FIG.1;

FIG. 3 a perspective exploded drawing of a further embodiment of aninventive hub;

FIG. 4a a view of a threaded ring according to the embodiment of FIG. 3;

FIG. 4b a cross section of a threaded ring according to the embodimentof FIG. 3;

FIG. 5a a view of a toothed disc from the embodiment according to FIG.3;

FIG. 5b a side view of a toothed disc according to the embodiment ofFIG. 3; and

FIG. 5c an enlarged detail view of the representation according to FIG.5b.

FIG. 1 shows hub housing 1 in a sectional view, said housing providedwith flanges 1 a and 1 b having bores at 1 c for the receiving ofspokes.

In virtually all bicycles, the pinion for the drive, respectively thederailleur pinion assemblage, is arranged on the right side of a bicyclewith respect to direction of travel. Accordingly, the following willalso refer to the left and right sides of the hub, whereby theorientation of FIG. 1 corresponds to the right.

In the left section of the hub, the housing comprises a cylindricalbearing bore 1 d, opened facing away from the hub center and in which aconventional grooved ball bearing 2 is disposed, shown onlyschematically in the drawing. The outer ball race of the grooved ballbearing is supported by cylindrical bearing bore 1 d and the inner ballrace by axle 4. In the present embodiment, said axle 4 is made of steeland is disposed with encircling stopper 4 a at which the inner ball raceof said roller bearing 2 positions to be non-displaceable.

Said roller bearing is retained in this position by a left stopperelement 6, which is configured to be substantially rotationallysymmetrical and having a conical exterior which increases in diametertoward the hub center and with its interior of cylindricalconfiguration.

A lower annular edge 6 a of left stopper element 6 positions at theinner ball race of the roller bearing and does not take part in therotational movement of the hub body.

A cylindrical shoulder 6 b is provided at the end with the smallerdiameter intended for the drop-out in mounted state, onto which atoothed disc 7 made of steel is pressed, having gearing 7 a earmarkedfor said drop-out.

An annular groove 6 d is provided in cylindrical inner bore 6 c of leftstopper element 6 in which O-ring 8 is accommodated. The dimensions ofO-ring 8 and groove 6 d are conformed to one another such that africtional force is generated between the O-ring and the axle, inducingthe stopper element to be held to the axle, but which can be removedfrom the axle and then positioned back on the axle without the need forany special tool.

Left stopper element 6 is provided with an encircling slot 6 e, which incross section is of trapezoidal shape, facing said roller bearing, theouter surface 6 f of said slot being essentially parallel to the outersurface 6 g of the stopper element and the inner surface 6 h of saidslot being configured as cylindrical and rotationally symmetrical toaxle 4, whereby said outer surface 6 f and said inner surface 6 h areconnected by an annular surface 6 i running perpendicular to axle 4.

A stopper ring 10 is disposed between cylindrical stopper element 6 h ofsaid trapezoidal recess and the cylindrical recess 1 d of the hub body,which positions on the outer ball race of the roller bearing and onsurface 1 d and rotates together with same.

Contact ring 10 has an encircling projection 10 a which projects intothe recess, which is limited inwardly by a cylindrical surfacerotationally symmetrical to the axle and outwardly by a conical surfacerunning parallel to surface 6 f and to outer surface 6 g of the stopper.Both of said surfaces are connected by a surface extending perpendicularto axle 4.

An essentially V-shaped elastomer seal is disposed within trapezoidalrecess 6 e, wherein the seal is such configured that one arm of the V isof rectangular configuration and positions on the surfaces of saidrecess 6 i and the cylindrical surface 6 h, and wherein the second armof the V is inclined at an acute angle relative the inner cylindricalsurface and tapers upwardly. The opening of the V points radiallyoutward. The tapered tip 12 b of said second arm of the V forms a lipseal, its upper narrow surface supported at projection 10 a of disc 10.

A labyrinth seal is created by means of stopper element 6, hub body 1and ring 10 as well as projection 10 a. Seal gap 13 a is perpendicularto axle 4 and limited by a front surface 6 j of stopper element 6 and bya front surface 1 e of the hub body. A cylindrical surface 6 k isprovided at a right angle to surface 6 j which, together withcylindrical surface 1 f, limits seal gap 13 b and extends perpendicularto seal gap 13 a and hence parallel to the axle. A further annularsurface 6 l adjoins cylindrical surface 6 k, which extends perpendicularto axle 4 and, together with the upper section of ring 10, the surfaceof which is likewise perpendicular to the axle, limits seal gap 13 crunning perpendicular to the axle.

A surface 6 j outwardly limiting recess 6 e is arranged at an obtuseangle to surface 6 k, which together with the likewise outwardly facingsurface 10 a of the projection of ring 10 limits seal gap 13 d extendingat an obtuse angle to gap 13 c.

The function of this part of the hub is as follows:

When mounting, axle 4 is inserted into hub body 1. Roller bearing 2 a isthen slid onto the axle with its inner ball race positioning at stopper4 a and its outer ball race at stopper 1 b of the hub body.

Subsequently, ring 10 is slid on and the V-shaped seal as well as theO-ring 6 d inserted into stopper element 6. The stopper is thenpositioned on the axle and secures the roller bearing.

In order to perform maintenance on the roller bearing, only element 6needs to be removed for the roller bearing to then be freely accessibleand removable from the axle.

The labyrinth-type seal, formed by gaps 13 a, b, c, d, prevents theinfiltration of water and dirt to a great degree. Since the sealingworks without contact, there is, no friction. Due to the multipledeflections of the seal gap, it is not possible for even a direct impactof a stream of water from a high-pressure cleaner to penetrate intorecess 6 e.

In the event that water does actually enter into recess 6 e, thecontacting elastomer seal reliably prevents same from advancing on tothe bearing. Due to the special protection afforded the elastomer sealby the labyrinth seal, there is no direct penetration of water intorecess 6 e and thus neither is there any pressuring of lip 12 b from ajet of water. Therefore, lip 12 b can be configured to be of lesselasticity and less pressure strength than would otherwise be possible,further decreasing the friction between the lip and the ring as aresult.

Should water penetrate into recess 6 e despite the labyrinth seal, thiswater is expelled back out by the centrifugal action of the ring and therotating sides of the seal gap.

In a variation of the present embodiment, which has been described withreference to FIGS. 1, 2 a and 2 b, it is also possible to omit ring 10and/or ring 40. In this case, the sealing is found directly on the ballrace of the respective roller bearing. This configuration has thedisadvantage that it does not have the correspondingly good sealingeffect as in the embodiment according to FIGS. 2a and 2 b, but on theother hand, it does in contrast have an advantage in that the relatedexpenditure is less since rings 10 and 40 are no longer necessary andalso since the weight and the assembly effort as a whole is less.

A cylindrical recess 1 g is disposed at the hub's right side,corresponding to cylindrical recess 1 d and accommodating a rollerbearing 2 b, corresponding to roller bearing 2 a. In correspondingmanner, a stopper 4 b is also provided for supporting the inner ballrace of the roller bearing.

A threaded ring 20 is screwed into a further cylindrical shoulder 1 h,the diameter of which is greater than shoulder 1 g, and which forms afreewheel in conjunction with a spring 21, a first toothed disc 22 and asecond toothed disc 23, as will be described later.

A rotor 25 is subsequently provided on hub body 1 having gearing 25 awhich engages in the correspondingly configured recess of a (not shown)pinion assemblage.

Rotor 25 is likewise made of aluminum or another light metal alloy suchas titanium, etc. During the drive motion, the rotor rotates at the samespeed as hub body 1 and remains stationary when the crank drive is atstandstill so that hub body 1 then moves relative to rotor 25.

The rotor is braced against axle 4 by roller bearing 2 c and rollerbearing 2 d, whereby said roller bearings in turn have the samedimensions as roller bearings 2 a and 2 b.

FIG. 3 shows a further embodiment of the hub according to the presentinvention in an exploded perspective view. Accommodated on axle 4, fromthe left, is a ball bearing 2 a, a cover ring 10, a seal 12, an O-ring 8and terminal stopper 6 with knurled disc 7. Following insertion into hubhousing 1, threaded ring 20 is screwed into hub housing 1 from theright, and then seal 12, ball bearing 2 b and spacer sleeve 30 areintroduced into said hub housing.

Coil spring 21 supports the floating mounting of toothed disc 22 so thatsame may be tilted relative the axial line of axle 4 and axiallydisplaceable against the force of coil spring 21.

The teeth of toothed disc 22 are directed to adjacent toothed disc 23 atits right, the teeth of toothed disc 23 correspondingly directed towardtoothed disc 22.

Toothed disc 23 is full floating-mounted by a further coil spring 21 andcan likewise be tilted relative the axial line of axle 4.

The two coil springs 21 press toothed discs 22 and 23 together and thefull floating support afforded by coil springs 21 enables said discs totilt together jointly with respect to the axial line of axle 4.

Flexible coil springs 21 induce a full floating support of toothed discs22 and 23 such that upon a slight tilting of one toothed disc, the othertoothed disc is likewise correspondingly tilted at the same time andthus ensures a flat contact of the teeth sides of the tooth discs. Thisenables as many teeth as possible on both toothed discs to be inconstant engagement when forward rotational force is transferred.

Also, the use of two springs results in less loading on each individualspring and additionally in greater acceleration at the outset, so thatengagement of the toothed discs' teeth transpires faster.

A ball bearing 2 c, a retaining ring 32, a spacer sleeve 31, anotherretaining ring 32, a ball bearing 2 d and a cover disc 38 are arrangedin rotor 25.

Furthermore, arranged from the right, is seal 38, an O-ring 42, terminalstopper 36 and knurled disc or gearwheel 27.

FIG. 4a represents a view of a threaded ring which in the embodiment asdepicted is made of aluminum alloy and its surface has been tempered ina surface treatment procedure. In addition to hardening with nicotine(in German: Nikotieren) or anodizing, other surface tempering proceduresknown in the prior art are also possible.

Threaded ring 20 is of cylindrical shape. Threading 42 is shown on theouter surface while teeth 40 and recesses 41 between said teeth areshown on the inner circumference.

FIG. 4b depicts a cross section through a threaded ring 20. A threading42 is arranged across the entire outer surface, while teeth 40 andrecesses 41 are disposed across the longitudinal extension.

FIG. 5a represents a view of a toothed disc 22 or 23.

Radial projections 60 and recesses 61 between said radial projectionsare distributed evenly across the circumference. The present embodimentemploys 26 projections to form a radial gearing.

FIG. 5b represents a side view of the toothed disc according to FIG. 5a.Radial projections 60 and recesses 61 are arranged distributed acrossthe circumference.

FIG. 5c shows an enlarged detail view of X from FIG. 5b. The teeth oftoothed disc 70 have a vertical rise of just under 1 mm compared to thedeepest point of recess 71.

The angle between inclines 72 and the center axis of the toothed discamounts to approximately 79.2° and the angle of inclines 73 to thecenter axis is roughly 10°. The angles as given are to be considered asguidelines and in other embodiments may vary by up to 10°.

A rotor 25 having a gearing 25 a is subsequently disposed on hub body 1which engages in the correspondingly configured recess of a (not shown)pinion assemblage.

Rotor 25 is likewise made of aluminum or another light metal alloy suchas titanium, etc. During the drive motion, the rotor rotates at the samespeed as hub body 1 and remains stationary when the crank drive is atstandstill so that hub body 1 then moves relative to rotor 25.

The rotor is braced against axle 4 by roller bearing 2 c and rollerbearing 2 d, whereby said roller bearings in turn have the samedimensions as roller bearings 2 a and 2 b.

A labyrinth seal with downstream elastomer seal is configured betweenhub body 1 and rotor 25, which will now be described with reference toFIG. 3.

Hub body 1 has an annular wall 1 k running perpendicular to axle 4, atwhich a cylindrical wall 1 l extending parallel to the axle adjoins atan angle of 90°. A further annular surface 1 m adjoins perpendicularlyin turn thereto, which likewise passes at 90° into a cylindrical region1 n, and then adjoined by vertical wall 1 o. Said annular wall 1 o andcylindrical wall 1 n encircle a recess in which an elastomer seal 28 isaccommodated. Said elastomer seal is of V-shaped configuration and hasan essentially rectangular cross-sectional portion 28 a which forms anarm of the V and an adjoining portion 28 b coming to a point, of whichthe front tip 28 c forms a lip seal.

At the contact point with the hub body, the rotor has (as seen radiallyinwardly) a vertically arranged annular area (previously gearing) 25 a,a cylindrical outer surface 25 b arranged at an angle of 90° theretofacing said rotor, another annular surface 25 c, a cylindrical outersurface 25 d adjoining thereto and then another annular surface 25 e.

A conical surface 25 f is subsequently provided adjoining annularsurface 25 e at an obtuse angle in cross section to which annularsurface 25 g adjoins, at which in turn a conically extending wall 25 hin cross section adjoins at an obtuse angle.

Walls 25 f, 25 h enclose a recess 25 i. A seal 28 engages in said recess25 i such that the tip 28 c of one of the arms of the V rests on surface25 h. Said surfaces 1 k, 1 l, 1 m together with each respectively facingsurface 25 a, 25 b, 25 c form a labyrinth seal.

The function of this seal and the downstream elastomer seal correspondsto the previously described function of the seal at left stopper element6. Since this part of the hub is protected by the pinion assemblage whenin operation, fewer deviations of course are necessary here for thelabyrinth seal as with left stopper element 6. In the left part of thehub as well, fluids are expelled in like manner outward upon rotation,whereby with this seal, in contrast to the seal in stopper element 6,the elastomer seal itself also rotates with the rest and thus any liquidadhering to same is likewise expelled outward due to centrifugal force.

Bearings 2 b and 2 c are kept at a distance from one another bycylindrical ring 30. A corresponding cylindrical ring 31 is disposedbetween bearing 2 c and bearing 2 d arranged at the extreme right. Inorder to retain the outer ring of bearing 2 c with respect to the rotor,a retaining ring 32 is provided, supported on the outer ball race ofbearing 2 c.

A right stopper element 36 is provided on the right side of the hubconsisting of a cylindrical shoulder 36 a which is accommodated in thedrop-out and a cylindrical shoulder 36 b of larger diameter having afurther cylindrical shoulder 36 c, in which a gearwheel 27 made of steelis accommodated in the same manner as with the left stopper element andwhich supports the stopper element at the drop-out.

A further cylindrical shoulder 36 d having a somewhat smaller diameteras shoulder 36 b, is disposed adjacent to cylindrical surface 36 b inthe direction of hub body 1, in which seal 38 is accommodated. Thiselastomer seal has a ring as its base body with an essentiallyrectangular cross section 38 a, from which sealing lip 38 b extendsradially outwardly at an angle of about 45° and on to form tip 38 c.

Tip 38 c is supported at stopper ring 40 which is retained in acylindrical recess 25 k of rotor 25 and has a cylindrical radialshoulder 40 a extending parallel to axle 4 a and on which surface 38 cof the front portion of seal 38 positions.

In the same manner as with the left stopper element, a groove 36 e isprovided for the right stopper element which receives an O-ring seal 42.Said O-ring seal is dimensioned with respect to groove 36 e such that itholds the right stopper element to the axle by means of friction.

The assembly of the right part of the hub corresponds substantially tothe assembly of the left part: the roller bearing 2 b, the fitting forthe freewheel and the roller bearing 2 c are slid onto the axle. Therotor with retaining ring is then positioned and the cylindrical ring 31and roller bearing 2 d follow as does ring 40. Then the stopper elementwith the seal can be slipped on and held by the frictional force of theO-ring. A special tool or a bolting of the individual parts to oneanother is not required.

For mounting on the bicycle, a conventional quick-release or othercorresponding mounting device is inserted into the longitudinal bore 4 cof the axle and the hub is affixed to the bicycle in such a manner thanthe inner surfaces of the drop-out abut against toothed discs 7 and 37.In this manner, the hub is held together reliably during operation.

What is claimed is:
 1. Hub, for bicycles having a hub axle, a hubhousing arranged essentially concentric to said hub axle, at least onebearing means comprising at least two bearings and which is arrangedessentially between said hub axle and said hub housing so that said hubhousing is mounted rotatably relative said hub axle, a rotor mountedrotatably relative said hub axle which is configured such that at leastone gearwheel may be arranged thereon, a freewheel device arrangedbetween said rotor and said hub housing and comprising two tootheddiscs, their toothed surfaces pressed together by means of apre-tensioning device, wherein said two toothed discs are arrangedessentially concentric to said hub axle and upon said hub beingassembled accordingly are arranged substantially in a planeperpendicular to an axial line of said hub axle, at least in the stateof rest, and wherein said toothed discs are retained in a floatingmounting so that a tilting perpendicular to said axial line of said hubaxle in relation to the plane is possible, and wherein saidpre-tensioning device comprises at least two springs, and wherein saidpre-tensioning device urges each of said adjacent two toothed discstogether from both exterior sides with at least one respective spring.2. Hub according to claim 1, wherein said toothed discs are exchangeableand no tools are needed.
 3. Hub according to claim 1, wherein at leastone of said springs of said pre-tensioning device is configured as acoil spring.
 4. Hub according to claim 1, wherein one of said springs ofsaid pre-tensioning device supports a floating mounting of one tootheddisc so that said toothed disc is axially displaceable against the forceof said spring and tiltable relative said plane perpendicular to saidaxial line of said axle.
 5. Hub according to claim 1, wherein the atleast two springs of said pre-tensioning device support the floatingmounting of said two toothed discs.
 6. Hub according to claim 1, whereina plurality of teeth are arranged at least on the facing disc surfacesof said toothed discs, wherein the number of said teeth is between 2 and48.
 7. Hub according to claim 6, wherein said plurality of said teethare arranged on an annular section of said disc surface of said tootheddisks.
 8. Hub according to claim 6, wherein said two toothed disks areessentially identical or are manufactured such that in the case of twotoothed discs arranged with directly adjacent tooth surfaces, at least aportion of the teeth of said first toothed disc comes into contact withrecesses between said teeth of said second toothed disc.
 9. Hubaccording to claim 6, wherein said toothed discs have a differing numberof teeth.
 10. Hub according to claim 6, wherein said toothed discs havean identical number of teeth.
 11. Hub according to claim 1, wherein whensaid tooth surfaces of said two toothed discs are engaged, said tootheddiscs are essentially in contact over a major portion of the discsurfaces.
 12. Hub according to claim 1, wherein at least one of saidtoothed discs has a plurality of projections distributed radially aboutthe circumference of same, which exhibit in the radial direction arectangular, sinusoidal, trapezoidal or toothed-shaped cross section ina plane of said disc surface.
 13. Hub according to claim 12, wherein oneof said toothed discs is arranged in a substantially concentric bore oropening in the rotor aligning to the center of the hub and non-rotatablerelative said rotor in the corresponding assembly and that said openingis configured such that said projections of said toothed discs extendinto the radial recesses of said rotor.
 14. Hub according to claim 12,wherein a threaded ring is screwed into said hub housing in asubstantially concentric bore of said hub housing aligning to said rotorin the corresponding assembly, having a bore in which a toothed disc isarranged essentially non-rotatable relative said hub housing, and thatsaid bore in said threaded ring is configured such that said projectionsof said toothed disc project into the radial recesses of said threadedring.
 15. Hub according to claim 1, wherein said toothed discs have aplurality of teeth that are evenly distributed circumferentially. 16.Hub according to claim 15, wherein selected ones of the plurality ofteeth are circumferentially omitted.
 17. Hub according to claim 15,wherein the circumferential spacing between adjacent ones of theplurality of teeth varies.
 18. Hub according to claim 1, wherein saidrotor is removable manually without the need for any tools.
 19. Hubaccording to claim 14, wherein said threaded ring is made of a metalalloy.
 20. Hub according to claim 1, wherein a sealing means is providedwhich greatly prevents the infiltration of water and dirt into thebearing means.
 21. Hub according to claim 20, wherein said sealing meanscomprises at least one labyrinth seal.
 22. Hub according to claim 20,wherein said sealing means comprises at least one elastomer seal. 23.Wheel, for bicycles, having a hub having a hub axle, a hub housingarranged essentially concentric to said hub axle, at least one bearingmeans comprising at least two bearings and which is arranged essentiallybetween said hub axle and said hub housing so that said hub housing ismounted rotatably relative said hub axle, a rotor mounted rotatablyrelative said hub axle which is configured such that at least onegearwheel may be arranged thereon, a freewheel device arranged betweensaid rotor and said hub housing and comprising two toothed discs, theirtoothed surfaces pressed together by means of a pre-tensioning device,wherein said two toothed discs are arranged essentially concentric tosaid hub axle and upon said hub being assembled accordingly are arrangedsubstantially in a plane perpendicular to an axial line of said hubaxle, at least in the state of rest, and wherein said toothed discs areretained in a floating mounting so that a tilting perpendicular to saidaxial line of said hub axle in relation to the plane is possible,wherein said pre-tensioning device comprises at least two springs, andwherein said pre-tensioning device urges each of said adjacent twotoothed discs together from both exterior sides with at least onerespective spring.
 24. Multi-wheel, having at least one hub having a hubaxle, a hub housing arranged essentially concentric to said hub axle, atleast one bearing means comprising at least two bearings and which isarranged essentially between said hub axle and said hub housing so thatsaid hub housing is mounted rotatably relative said hub axle, a rotormounted rotatably relative said hub axle which is configured such thatat least one gearwheel may be arranged thereon, a freewheel devicearranged between said rotor and said hub housing and comprising twotoothed discs, their toothed surfaces pressed together by means of apre-tensioning device, wherein said two toothed discs are arrangedessentially concentric to said hub axle and upon said hub beingassembled accordingly are arranged substantially in a planeperpendicular to an axial line of said hub axle, at least in the stateof rest, and wherein said toothed discs are retained in a floatingmounting so that a tilting perpendicular to said axial line of said hubaxle in relation to the plane is possible, wherein said pre-tensioningdevice comprises at least two springs, and wherein said pre-tensioningdevice urges each of said adjacent two toothed discs together from bothexterior sides with at least one respective spring.